Highlighting cardiovascular manifestations of kleefstra syndrome: literature review and clinical insights

Kleefstra syndrome (KLEFS1) is a rare genetic disorder primarily caused by the deletion of the chromosome 9q34.3 genomic segment or pathogenic mutations in the euchromatin histone methyltransferase 1 (EHMT1) gene. It is characterized by intellectual disability or impairment, childhood hypotonia, and distinct facial features. Notably, cardiovascular defects especially congenital heart diseases also represent a major feature of KLEFS1. While the neuropsychiatric aspects of KLEFS1 have been extensively documented and researched, the cardiovascular manifestations have not received adequate attention. The majority of KLEFS1 patients often present with a spectrum of cardiovascular defects, including abnormal cardiac structure, arrhythmias, valve abnormalities, cardiomyopathy, and coronary artery abnormalities. Here, we systematically searched and reviewed previously published articles and case reports related to KLEFS1, conducting a comprehensive analysis of the existing literature to highlight the cardiovascular manifestations of this genetic disorder and explore the potential correlations between the cardiac phenotype and KLEFS1.